The Data Analyses and Biostatistics Core will facilitate the acquisition, tracking and processing of information for the Program Project Grant (PPG). Several projects will utilize the same acquisition and analyses procedures and our specialized computer programs developed in the previous PPG will be used for these analyses. Core C personnel will maintain a continuing dialog with project personnel on a regular basis to monitor data acquisition and processing and to modify experimental designs. Core C will provide the highest level of expertise in biostatistics for the design of the experiments and for formal demonstrations of significant experimental results. It will also provide support, development and maintenance of software and computer systems essential for the collection and analysis of data. Building on the progress from the previous PPG, we will continue to develop new analyses procedures with statistical modeling approaches.